1. Field of the Present Invention
The present invention relates to a wireless sensor network and, more particularly, to a communication method for a mobile sensor node in a wireless sensor network.
2. Description of the Related Art
A wireless sensor network is a key enabling technology for implementing a ubiquitous computing technology. In the wireless sensor network, a plurality of nodes may be connected to each other to operate in a wireless manner.
In the sensor network, since each node operates with a battery having a limited capacity, measured data need to be transmitted by using minimum energy. In addition, in order to adapt the sensor network to a real-time application system, transmission delay in a large-scale sensor network needs to be minimized. Therefore, for a sensor network requiring real-time monitoring, a protocol capable of minimizing energy consumption of the battery and decreasing the network transmission delay has been requested.
According to the request, the inventor filed Korean Patent Application No. 10-2007-0008935, titled “Wireless Sensor Network Having Linear Structure Performing Bidirectional Data Communication and Method” in Korean Intellectual Patent Office.
The patent application discloses a technology of performing bidirectional communication between a sync node and a terminal node in a single period of an active duration in a wireless sensor network which is constructed with a plurality of nodes and in which each node is connected to one upper node and one lower node so that the sync node through the terminal node are linearly connected, wherein each node includes an active duration in which data are transmitted and received with respect to the upper node and the lower node, wherein active duration includes a downlink active duration in which data/commands are transmitted from the sync node to the terminal node and an uplink active duration in which data/commands are transmitted from the terminal node to the sync node.
The aforementioned wireless sensor network has been widely used for watching a forest fire on a mountain or a sign of bridge collapse, detecting destruction of cultural assets. In order to improve the utility of the wireless sensor network, additional technology has been required to develop. Particularly, a technology of communication between the mobile sensor node and the wireless sensor network for implementing a real-time test, a missing child search service, or the like has been required to develop.